PHYSICS RESOURCE BOOK G13 UNIT 10

1. Elasticity

1.1 Introduction

1.2 Elastic and inelastic substances

1.3 Graphical illustration of change in extension values through a wire for different weights applied

1.4 Hooke’s Law

1.5 Modulus of elasticity

1.6 Tensile stress, tensile strain and Young’s modulus

1.7 Graph of stress against strain

1.8 Experimental determination of Young’s modulus of a metal wire

1.9 Energy stored in an extended wire

1.10 Forces produced in rods and wires clamped at both ends during temperature changes

1.11 Applications of elasticity in day-to-day life

2.Viscosity

2.1 Introduction

2.2 Streamline and turbulent motions

2.3 Definition of the coefficient of viscosity

2.4 Poiseuille’s equation

2.5. Motion of a small spherical body falling freely through a viscous medium

2.5.1 Stokes’ Law

2.5.2 Derivation of an expression for the termind velocity of a small spherical body moving through a viscous liquid

2.6 Ex-comparison of viscosities of different liquids

2.7 Application of viscosity

3. Surface Tension

3.1 Introduction

3.2 Explanation of surface tension using molecular theory

3.3 Cohesive forces and adhesive forces

3.4 Definition of surface tension

3.5 Shapes of liquid surfaces and angle of contact

3.6 The work done in increasing the surface area of a soap film

3.7 Expression for the pressure difference across a spherical  meniscus

3.8 Derivation of the expression for capillary rise due to surface tension

3.9 Methods of determining surface tension

3.10 Applications of surface tension